3rd Radiator for Street Use?

[achillies]

I live in Las Vegas...hot hot hot in summer. My 2000 6speed never moves above 180 (by the gauge) even w/AC. I cant help but wonder if Porsche tested their cars in desert climates? If they did the car should not overheat or run too hot. It would seem to me that if a car is running too hot then something in the system is not working as designed. I really dont get the whole discussion.

[perryinva]

That's why we're discussing it here. It doesn't make sense. Of course in Vegas it's a dry heat (insert joke) but maybe radiators cool better with dry air? It is often 100+ and 90%+ humidity in Richmond, and I agree, that as long as the car is moving, there is not an issue. Bruce is concerned in stop & go, so little or only fan air movement. Is there much heavy S&G traffic in Vegas?

[BruceP]

I live in Las Vegas...hot hot hot in summer. My 2000 6speed never moves above 180 (by the gauge) even w/AC. I cant help but wonder if Porsche tested their cars in desert climates? If they did the car should not overheat or run too hot. It would seem to me that if a car is running too hot then something in the system is not working as designed. I really dont get the whole discussion.

Echo perryinva's comments. I think the car is built to do what it does brilliantly, which is go fast. When my car is doing that, it's happy as a clam in any conditions. I don't think that Porsche failed to test the car for hot climates, but I bet they didn't give too much thought to designing it for sitting still.

To clarify my issue, the car is not overheating in the opinion of its designers (the warning light has never come on). It's ME who isn't comfortable with the operating temps when it's idling in traffic.

Regarding your temperature gage, I don't think mine "moves above 180" either. Problem is, on that gage, "180" covers a lot of territory. I use the OBD to get the actual temperature, if I really want to know. I'm pretty sure I've seen 105C on the OBD without the needle on the gage moving past the "180".

My original question was quite simple: Will the third radiator lower the coolant temperature appreciably in stop and go driving conditions? Three pages later, it doesn't look like anybody knows for certain. That kind of gave me my answer.

[RFM]

The third radiator will not lower the temperature in stop and go traffic (lack on fan), 997 2 has even no more.

[perryinva]

"997 2 has even no more" I'm sorry, what does that mean? Do you mean the 997 MKII engine still only has the same two radiators setup, and has 385HP? The 3rd radiator SHOULD help (it radiates with or without airflow, just much much better with airflow), but since I haven't installed one, I can not say how much. Bruce is right, of course, the "180" nuumbers on the temp gauge easily cover from 170 to 200, which I suspect is intentional.

Edited March 10, 2009 by perryinva

[Loren]

"997 2 has even no more" I'm sorry, what does that mean? Do you mean the 997 MKII engine still only has the same two radiators setup, and has 385HP? The 3rd radiator SHOULD help (it radiates with or without airflow, just much much better with airflow), but since I haven't installed one, I can not say how much. Bruce is right, of course, the "180" nuumbers on the temp gauge easily cover from 170 to 200, which I suspect is intentional.

I think RFM's point is that the 997-2 still has only two radiators.

[wvicary]

I don't think the third rad will lower temps. It will slightly increase the amount of coolant in the system but it will still heat to whatever temp it's reaching... just take a little long to reach it maybe and less time to lose that heat once you get moving again. I really wouldn't worry about it all.

[RFM]

997-2 has only the 2 conventional side radiators with fans, the engine cooling is increased by a higher capacity pump, improved and larger water channels inside the MA101/102 engine, improved airflow to the side radiators, cooling system capacity is between 29 and 31.50 litre depending on vehicle equipment, etc. All these interventions guarantee a sufficient cooling.

[catmanluge]

I added a third radiator and felt is was well worth the effort. On track days the temp would reach the high end of the guage. Now it stays in the normal range even while pushing hard on summer track days.

[LJPete]

My first 996 had the 3rd radiator and it would reach more or less the same temp as my 996 with 2 radiators (maybe slightly higher). With that said, it would cool much quicker once I started rolling or when the fans kicked in. It was kind of nerve racking at first seeing the temp needle move to the middle of the 0 in 180 and then the fans would kick in and the needle would head back to vertical quite quickly. With that said, my 996 with the 3rd radiator, the 2 main radiators where pretty dirty and where in need of a cleaning so temps might have been a bit better if they where cleaner.

My bone stock 996 now, rarely gets the needle up to the middle part of the zero in the 180 degree marking on the gauge. I suspect that this is due to the clean radiators it has when I bought it.

Edited March 11, 2009 by LJPete

[BruceP]

Sorry to bump an old thread, but I thought I'd share what looks like the real problem may have been.

There was significant corrosion in both radiators. It was bad enough that when my indie started to clean out the corroded material, one rad actually started to leak. I'm replacing both rads and refurbing the AC condensers, and I'll bet that cools things down.

My car is driven year round, even on salty, slushy days here in Toronto. It was interesting to me that the body and chassis are still in wonderful shape for all the abuse. Never imagined it would be the rads that would complain first.

Thanks again to those who were interested. And if you winter drive your car in salt and crap, maybe something to keep an eye on that you might not have thought of.

Bruce.

[perryinva]

Like we said, radiator cleaning is normally the culprit, in your case, it just wasn't leaves, but the result is the same. Salt is nasty stuff on aluminum. Would definitely pay to hose out the rads in wintertime to get the salt out. Glad you found it before you sprung aleak!

[BruceP]

Like we said, radiator cleaning is normally the culprit, in your case, it just wasn't leaves, but the result is the same. Salt is nasty stuff on aluminum. Would definitely pay to hose out the rads in wintertime to get the salt out. Glad you found it before you sprung aleak!

As I may have mentioned somewhere in this thread, the rads were 'clean' in the sense that debris had been removed. The corrosion developed in the outboard lower corners of the rads, which are of course behind the AC condensers. Regular hosings might help, but I suspect the only way to prevent it would have been to regularly remove the bumper cover and separate the rads and AC condensers as some here do from time to time.

It was somebody else's car for six winters, so caveat emptor. But this is the first car I've owned with aluminum rads. Never would have occurred to me. (That said, I like this problem better than BMW's plastic rads and the fun way they fail!).

[SH-GT3]

Like we said, radiator cleaning is normally the culprit, in your case, it just wasn't leaves, but the result is the same. Salt is nasty stuff on aluminum. Would definitely pay to hose out the rads in wintertime to get the salt out. Glad you found it before you sprung aleak!

As I may have mentioned somewhere in this thread, the rads were 'clean' in the sense that debris had been removed. The corrosion developed in the outboard lower corners of the rads, which are of course behind the AC condensers. Regular hosings might help, but I suspect the only way to prevent it would have been to regularly remove the bumper cover and separate the rads and AC condensers as some here do from time to time.

It was somebody else's car for six winters, so caveat emptor. But this is the first car I've owned with aluminum rads. Never would have occurred to me. (That said, I like this problem better than BMW's plastic rads and the fun way they fail!).

Glad you caught before a catastrophic event. Link

[perryinva]

Yeah, you can say that again. That plastic neck snapped on my 528 and cost $3k worth of engine damage...warped head, pulled block threads that had to be helicoiled, etc, etc. Until this happened to you, I'd not have though of it either, but of course those rads are just collectors for everything, as low as they are, but then I don't drive the 996 in what little snow we get, here in Richmond. I thought most all rads cooling portions are finned aluminum nowadays, so I'm surprised it doesn't happen more often up north. BTW, how much were the rads?

As I may have mentioned somewhere in this thread, the rads were 'clean' in the sense that debris had been removed. The corrosion developed in the outboard lower corners of the rads, which are of course behind the AC condensers. Regular hosings might help, but I suspect the only way to prevent it would have been to regularly remove the bumper cover and separate the rads and AC condensers as some here do from time to time.

It was somebody else's car for six winters, so caveat emptor. But this is the first car I've owned with aluminum rads. Never would have occurred to me. (That said, I like this problem better than BMW's plastic rads and the fun way they fail!).

[BruceP]

The rads were $425CDN each. I did both of them as a precautionary measure. They also sent the AC condensers out for reconditioning. I'm going to bet this solves it.

On the BMW cooling system topic, I was so paranoid about this that when I bought my 04 Range Rover last year, I put a significant amount of money into replacing every failure-prone cooling system component!

EDIT: Here are a couple of pics of the rotted rads.

Yeah, you can say that again. That plastic neck snapped on my 528 and cost $3k worth of engine damage...warped head, pulled block threads that had to be helicoiled, etc, etc. Until this happened to you, I'd not have though of it either, but of course those rads are just collectors for everything, as low as they are, but then I don't drive the 996 in what little snow we get, here in Richmond. I thought most all rads cooling portions are finned aluminum nowadays, so I'm surprised it doesn't happen more often up north. BTW, how much were the rads?

Edited April 6, 2009 by BruceP

[1999Porsche911]

The rads were $425CDN each. I did both of them as a precautionary measure. They also sent the AC condensers out for reconditioning. I'm going to bet this solves it.

On the BMW cooling system topic, I was so paranoid about this that when I bought my 04 Range Rover last year, I put a significant amount of money into replacing every failure-prone cooling system component!

EDIT: Here are a couple of pics of the rotted rads.

Yeah, you can say that again. That plastic neck snapped on my 528 and cost $3k worth of engine damage...warped head, pulled block threads that had to be helicoiled, etc, etc. Until this happened to you, I'd not have though of it either, but of course those rads are just collectors for everything, as low as they are, but then I don't drive the 996 in what little snow we get, here in Richmond. I thought most all rads cooling portions are finned aluminum nowadays, so I'm surprised it doesn't happen more often up north. BTW, how much were the rads?

If the bet is that your coolant temperature will stay below 215F while in traffic....I'll take that bet. :D

[BruceP]

If the bet is that your coolant temperature will stay below 215F while in traffic....I'll take that bet. :D

I don't think any practical mod would produce that result, actually, though I know you feel differently. But I'll be happy with any improvement, and delighted if I never saw the far side of 105C except in the very worst circumstances.

[1999Porsche911]

If the bet is that your coolant temperature will stay below 215F while in traffic....I'll take that bet. :D

I don't think any practical mod would produce that result, actually, though I know you feel differently. But I'll be happy with any improvement, and delighted if I never saw the far side of 105C except in the very worst circumstances.

Not my belief, but a fact. Why not just do the mod and be on your way?

Edited April 6, 2009 by 1999Porsche911

[perryinva]

So about $380 USD each..just the parts?! Sheesh!! Wow.

[BruceP]

So about $380 USD each..just the parts?! Sheesh!! Wow.

Could be worse. I wasn't that fussed about it. Porsches are cheap to buy, but not cheap to own. This has always been true. A lot of guys aren't ready for that. I like to fix these things right, I don't mind paying for it, and I've never had a single repair item that exceeded the equivalent of a single monthly payment on a newer one. I'm not complaining. (But you'd be surprised at the heat I've taken in 'other' forums for not being upset about maintenance costs!)

[SH-GT3]

People pay that and more for 1 tire. The radiators, when taken care of, I'm sure will last 10s of years

[Loren]

So about $380 USD each..just the parts?! Sheesh!! Wow.

My 3rd radiator kit (for my 996) was about $400 in 2000. I thought that was a great deal because when I added up the parts priced individually they were over $600.

So, I still think a price under $400 is very good.

[seafeye]

So about $380 USD each..just the parts?! Sheesh!! Wow.

My 3rd radiator kit (for my 996) was about $400 in 2000. I thought that was a great deal because when I added up the parts priced individually they were over $600.

So, I still think a price under $400 is very good.

Got the center radiator on Ebay for $100 plus $20 for shipping and then got all the rest of the parts from the sponsor of this web site...for $232.

So for $352 i have all that's needed for the conversion. Oh maybe another $10 for a screen and trim. My bumper doesn't have the cutout.

[perryinva]

I'd like to see pics of your install when done. For those that have done the 3rd rad, do they catch a lot of crud, being so low and exposed there?